watcherd

watcherd will look for directory changes (added and deleted directories) under the specified path (-p) and will execute specified commands or shell scripts (-a, -d) depending on the event. Once all events have happened during one round (-i), a trigger command can be executed (-t). Note, the trigger command will only be execute when at least one add or delete command has succeeded with exit code 0.

If you need the same functionality to monitor changes of listening ports, check out watcherp.

Modes

watcherd can either use the native inotifywait implementation or if this is not available on your system use a custom bash implementation. The default is to use bash.

Placeholders

There are two placeholders available that make it easier to use custom commands/scripts for the add (-a) or delete (-d) action.:

%p Full path to the directory that was added or deletd
%n Name of the directory that was added or deleted

You can specify the placeholders as many times as you want. See the following example section for usage.

Examples

By using vhost-gen (which is capable of creating Nginx or Apache vhost config files for normal vhosts or reverse proxies), the following will be able to create new nginx vhosts on-the-fly, simply by adding or deleting folders in your main www directory. The trigger command will simply force nginx to reload its configuration after directory changes occured.

# %n will be replaced by watcherd with the new directory name
# %p will be replaced by watcherd with the new directory path
watcherd -v \
  -p /shared/httpd \
  -a "vhost-gen -p %p -n %n -s" \
  -d "rm /etc/nginx/conf.d/%n.conf" \
  -t "nginx -s reload"

Usage

Usage: watcherd -p <path> -a <cmd> -d <cmd> [-t <cmd> -w <str> -i <int> -v -c]
       watcherd --help
       watcherd --version

watcherd will look for directory changes (added and deleted directories) under
the specified path (-p) and will execute specified commands or shell scripts
(-a, -d) depending on the event. Once all events have happened during one round
(-i), a trigger command can be executed (-t). Note, the trigger command will
only be execute when at least one add or delete command has succeeded with exit
code 0.

Required arguments:
  -p <path>     Path to directoy to watch for changes.
  -a <cmd>      Command to execute when a directory was added.
                You can also append the following placeholders to your command string:
                %p The full path of the directory that changed (added, deleted).
                %n The name of the directory that changed (added, deleted).
                Example: -a "script.sh -f %p -c %n -a %p"
  -d <cmd>      Command to execute when a directory was deletd.
                You can also append the following placeholders to your command string:
                %p The full path of the directory that changed (added, deleted).
                %n The name of the directory that changed (added, deleted).
                Example: -d "script.sh -f %p -c %n -a %p"

Optional arguments:
  -e <regex>    Exclude regex for directories to ignore.
                E.g.: -e '\.*' to ignore dot directories.
  -t <cmd>      Command to execute after all directories have been added or
                deleted during one round.
                No argument will be appended.
  -w <str>      The directory watcher to use. Valid values are:
                'inotify': Uses inotifywait to watch for directory changes.
                'bash':    Uses a bash loop to watch for directory changes.
                The default is to use 'bash' as the watcher.
  -i <int>      When using the bash watcher, specify the interval in seconds
                for how often to look for directory changes.
  -v            Verbose output.
  -c            Colorized log output.

Misc arguments:
  --help        Show this help screen.
  --version     Show version information.

License